Comparison of the Effects of Intra-Articular Corticosteroid Injection and Intra-Articular Laser Therapy in Patients with Knee Osteoarthritis

To compare the efficacy of single dose intraarticular corticosteroid injection and intraarticular low level laser therapy in knee osteoarthritis in terms of pain, osteoarthritis outcomes, quality of life, and adverse events.

A phase II, randomized, controlled, parallel group, double blind clinical trial involving 54 patients. Block randomization with a block size of 6 will be performed using Random Allocation Software.

This clinical trial will be conducted at the Physical Medicine and Rehabilitation Clinic of Firoozgar Hospital, Tehran. Patients will receive either intraarticular injection of 40 mg triamcinolone or intraarticular laser therapy. Procedures will be ultrasound guided, with participant and outcome assessor blinding.

Patients aged 45 to 75 years with knee osteoarthritis diagnosed by ACR clinical and radiographic criteria, Kellgren Lawrence grade 2 or 3, and a pain score of at least 4 of 10 will be included. Major exclusions include recent joint injection, surgery or planned arthroplasty, inflammatory or secondary arthritis, bleeding risk, infection, malignancy, diabetes, pregnancy, breastfeeding, relevant medication use, or hypersensitivity. Withdrawal includes withdrawal of consent, new exclusion criteria, loss to follow up, serious adverse events, nonadherence, or protocol violation.

Group A receives ultrasound guided intraarticular triamcinolone acetonide, 40 mg in 1 mL, plus sham laser. Group B receives intraarticular laser therapy, 658 nm, 50 mW, for 20 minutes, delivering 60 J, plus sham injection of 0.5 mL normal saline.

Pain will be assessed by the Visual Analogue Scale (VAS) and function by the validated Persian Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, week 1, and month 1. Adverse events will be recorded.

Participants will be allocated to one of two treatment groups using block randomization with a block size of 6: Group 1: Intra-articular corticosteroid injection Group 2: Intra-articular laser therapy (IALT) For randomization, a set of small papers of identical size, color, and material will be prepared. Each paper will be labeled with a number indicating the treatment group (number 1 for corticosteroid injection and number 2 for laser therapy). Based on a sample size of 54 participants, nine complete blocks, each containing 6 participants, will be designed. Within each complete block, three allocations will be assigned to Group 1 and three allocations to Group 2. The sequence of group assignments within each block will be generated completely at random using Random Allocation Software.

This study is designed as a double-blind trial; both the participants and the personnel responsible for completing the questionnaires will be unaware of treatment-group allocation. However, given the practical and ethical limitations arising from the inherent differences between the interventions (drug versus energy), complete blinding of the interventionist is not feasible in this protocol. Therefore, the primary focus will be on maintaining blinding of participants and outcome assessors. Group A (Corticosteroid): Participants will receive an ultrasound-guided intra-articular injection of 40 mg triamcinolone acetonide. To simulate the laser procedure, an inactive optical fiber with a visible red indicator light will be introduced through the same needle, without delivery of therapeutic energy. Group B (Laser therapy): Participants will receive intra-articular laser therapy using a 658-nm wavelength (red light) at a power of 50 mW for 20 minutes (total energy: 60 J), delivered through a sterile optical fiber inserted using a 22-gauge needle. To simulate drug injection, 0.5 mL of normal saline will be injected and subsequently aspirated/reinjected to reproduce the physical sensation of an injection. To assess the success of blinding, participants and outcome assessors will periodically be asked to guess the assigned treatment group. These data will be recorded and evaluated in sensitivity analyses to assess the potential impact of lack of interventionist blinding on the study results.

All data is shareable, provided it has been fully de-identified.

Access will be available starting 6 months after the publication of the results.

Access is restricted to researchers affiliated with academic and scientific institutions.

For future research use, please submit a written request via email.

Principal Investigator: Dr. Bijan Forogh Email: forogh.b@iums.ac.ir

Upon submission of your request, data access will be provided within approximately one week.